N-GLYCOSIDASE FROM ESCHERICHIA-COLI THAT RELEASES FREE URACIL FROM DNA CONTAINING DEAMINATED CYTOSINE RESIDUES
N-GLYCOSIDASE FROM ESCHERICHIA-COLI THAT RELEASES FREE URACIL FROM DNA CONTAINING DEAMINATED CYTOSINE RESIDUES
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DOI：
10.1073/pnas.71.9.3649
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发表时间：
1974-01-01
影响因子：
11.1
通讯作者：
LINDAHL, T
中科院分区：
文献类型：
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作者：
LINDAHL, T
一种从含有脱氨基胞嘧啶残基的单链和双链DNA以及在没有镁++的情况下从脱氧胞苷-脱氧尿苷共聚物中释放尿嘧啶的酶已经从E。Coli.该酶不从脱氧尿苷、DUMP、尿苷或RNA中释放尿嘧啶，也不从DNA中释放正常存在的嘧啶碱基，胞嘧啶和胸腺嘧啶。DNA中n-糖苷键的酶促断裂不伴随磷酸二酯键的断裂，导致游离尿嘧啶和含有脱嘧啶中心作为反应产物的链长不变的DNA链的形成。这种酶在DNA修复中可能是活跃的，将脱氨基的dCMP残基转化为易于修复的形式。
An enzyme that liberates uracil from single-stranded and double-stranded DNA containing deaminated cytosine residues and from deoxycytidylate-deoxyuridylate copolymers in the absence of Mg++has been purified 30-fold from cell extracts ofE. coli. The enzyme does not release uracil from deoxyuridine, dUMP, uridine, or RNA, nor does it liberate the normally occurring pyrimidine bases, cytosine and thymine, from DNA. The enzymatic cleavage ofN-glycosidic bonds in DNA occurs without concomitant cleavage of phosphodiester bonds, resulting in the formation of free uracil and DNA strands of unaltered chain length that contain apyrimidinic sites as reaction products. The enzyme may be active in DNA repair, converting deaminated dCMP residues to an easily repairable form.